Polyester resins have widely been used as materials of bottles, films, fibers, toner binders, etc.
Patent Document 1 teaches a method for producing the polyester resin. According to this method, bisphenol A and terephthalic acid are introduced in a reactor, and pressure in the reactor is increased while stirring the materials to esterify them. A catalyst is then added to the reactor, the reactor is evacuated, and a diol component is removed from the reaction system to condensation-polymerize the remaining product.
Patent Document 2 teaches a method of mixing ethylene glycol and dicarboxylic acid, esterifying the materials in a normal pressure state or a pressurized state, and condensation-polymerizing the resulting product with the normal pressure state changed to a depressurized state.
Patent Document 3 teaches a method of mixing ethylene glycol and terephthalic acid, esterifying the materials in a pressurized state while water is removed from the system by evaporation at all times to obtain a low molecular weight condensate, and adding a catalyst to the low molecular weight condensate to condensation-polymerize the low molecular weight condensate.
Citation List
Patent Documents
[Patent Document 1] Japanese Patent Publication No. H06-138702
[Patent Document 2] Japanese Patent No. 3690255
[Patent Document 3] International Patent Publication No. WO2004/111105